A top-down integration approach to vehicle stability control

For vehicles equipped with co-existing active systems of steering, driving and braking, in order to avoid subsystem interferences and further exploit performance improvement potential, a top-down integrated controller with main/servo- loop structure is designed. Firstly, a sliding mode controller in the main-loop calculates the generalized stabilizing forces. Then in the servo-loop, a control allocation approach based on constrained quadratic programming is adopted to reasonably and optimally distribute these generalized stabilizing forces to tire force vector, which will be further converted to wheel control torques and active steering angles using inverse tire model and slip controller. Co-simulation of Matlab/Simulink and MSC CarSim clarifies that by directly considering actuator limits, the proposed controller can significantly improve vehicle handling performances.